
Ultraviolet - Wikipedia
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the …
Ultraviolet Radiation: How It Affects Life on Earth
Ultraviolet (UV) radiation that reaches the Earth’s surface is in wavelengths between 290 and 400 nm (nanometers, or billionths of a meter). This is shorter than wavelengths of visible light, which are 400 to 700 nm. People and plants live with both helpful and harmful effects of ultraviolet (UV) radiation from the sun.
UV Photons
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Ultraviolet (UV) Radiation | FDA
All EM radiation (also called EM energy) is made up of minute packets of energy or 'particles,' called photons, which travel in a wave-like pattern and move at the speed of light. The EM spectrum...
Ultraviolet Radiation - an overview | ScienceDirect Topics
Ultraviolet radiation refers to a form of electromagnetic radiation with wavelengths shorter than visible light, divided into UVC, UVB, and UVA fractions. It carries higher energy photons than visible light and can have harmful effects on DNA, leading to …
Ultraviolet Waves - NASA Science
2016年8月10日 · NASA's SDO spacecraft captured the image below in multiple wavelengths of extreme ultraviolet (EUV) radiation. The false-color composite reveals different gas temperatures. Reds are relatively cool (about 60,000 Celsius) while blues and greens are hotter (greater than one million Celsius).
Electromagnetic Spectrum - Introduction
2014年11月14日 · Electromagnetic radiation can be described in terms of a stream of mass-less particles, called photons, each traveling in a wave-like pattern at the speed of light. Each photon contains a certain amount of energy. The different types of radiation are defined by the the amount of energy found in the photons.
Ultraviolet (UV) Radiation - Center for Science Education
Ultraviolet radiation lies between visible light and X-rays along the electromagnetic spectrum. UV "light" spans a range of wavelengths between about 10 and 400 nanometers. The wavelength of violet light is around 400 nanometers (or 4,000 Å). Ultraviolet radiation oscillates at rates between about 800 terahertz (THz or 10 12 hertz) and 30,000 THz.
How Ultraviolet Light Reacts in Cells - Nature
2015年2月14日 · When melanin is hit by a photon of UV light, it goes into an excited state, where an electron has increased in energy. In chlorophylls, this excited state starts the chain of reactions that ...
29.3: Photon Energies and the Electromagnetic Spectrum
A UV photon has sufficient energy to ionize atoms and molecules, which makes its effects different from those of visible light. UV thus has some of the same biological effects as rays and x rays. For example, it can cause skin cancer and is used as a sterilizer.